Disk-type optical data recorders have received a lot of attention and development. One of the prime design concerns is to have an optical head that is extremely lightweight, such that it can be radially moved with respect to a rotating optical record member. This feature is extremely important when the optical signal recorders are employed in a data processing environment. In such environments, time is extremely valuable; therefore, anything that reduces access time to recorded signals can have a salutary effect on the operation of the data processing environment.
Another aspect is cost. It is highly desirable that ease of manufacture, ease of maintenance plus low cost be achieved in all apparatus. This goal, combined with the requirement that the optical head be extremely lightweight, presents formidable problems to a designer. Accordingly, it is desired to have an extremely light-weight, easily-adjustable optical transducer for providing a new optical data recorder having enhanced access time at low cost.
It is also desired for purposes of recording integrity that the signals just recorded can be read back for verifying the recording operation. Such operations are often called DRAW for direct-read-after-write. DRAW eliminates waiting one revolution of a disk for verifying recording. With the advent of semiconductive lasers, which are quite light-weight, a two-laser head assembly becomes more feasible for enabling DRAW. The optical components of an extremely small assembly must not only be lightweight but easily adjustable.